<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>form表单</title>
</head>
<body>
<form action="https://www.google.com/">
  用户名: <input type="text" name="username" placeholder="username" ><br>
  密码: <input type="password" name="password" placeholder="password" maxlength="6"><br>
<!--maxlength限制输入长度  -->
  性别：<br>
  <input type="radio" name = "gender" value="1">男
  <input type="radio" name="gender" value="0" checked>女
  <input type="radio" name = "gender" value="???"> 不可告知
  <br>
<!--  name统一可以保证多选一-->
  爱好：<br>
  <input type="checkbox" name = "hobby" value="smoke">抽烟
  <input type="checkbox" name = "hobby" value="drink">喝酒
  <input type="checkbox" name = "hobby" value="perm">烫头
  <input type="checkbox" name = "hobby" value="java" checked>学java
  <!--checked默认选中-->
  <br>
  <input type="date" name = "birthday">
  <br>
  <input type="file" name = "img">
  <br>
  <select name="city" id="">
    所在地:
  <option value="bj">北京</option>
  <option value="sh" selected>上海</option>
  <option value="gz">广州</option>
</select>

  <br> <input type="submit" value="点我提交信息">
  <br><input type="reset" value="重置选择">
  <input type="button" value="一般路过普通按钮" onclick="alert('我就猜你要点我')">
  <button>按钮等价于onclick</button>
  <hr>
  <input type="checkbox" id="agree">
  <label for="agree">我同意相关协议</label>
<!--  关联标签，即使点字也能实现点到小按钮-->
</form>
</body>
</html>